CN216994057U

CN216994057U - Slope system

Info

Publication number: CN216994057U
Application number: CN202123097557.6U
Authority: CN
Inventors: 李贤雨; 卞志洙; 柳成敏; 金世勋
Original assignee: Hyundai Motor Co; Kia Corp
Current assignee: Hyundai Motor Co; Kia Corp
Priority date: 2021-06-25
Filing date: 2021-12-10
Publication date: 2022-07-19
Anticipated expiration: 2031-12-10
Also published as: US20220410783A1; KR20230000667A

Abstract

A ramp system is configured to move a pedal disposed in a frame in a direction of movement between a ramp closed position and a ramp open position. The ramp system may include: a driving device including a pair of sprockets spaced apart from each other in a moving direction and rotatably provided in the frame, and a chain engaged with the pair of sprockets and movable in the moving direction and transmitting a driving torque to the pedal to move the pedal in the moving direction; and a tensioner including a tension rod rotatably installed in the frame, one end of the tension rod being connected to the tension spring to receive an elastic force, and a tension gear engaged with the chain being rotatably installed at the other end of the tension rod to apply a tension force to the chain.

Description

Slope system

Cross Reference to Related Applications

This application claims priority and benefit from korean patent application No. 10-2021-.

Technical Field

The present disclosure relates to a ramp system, and more particularly, to a ramp system of a vehicle, which can prevent a fluctuation of a pedal and reduce noise of a driving device when the pedal enters and exits a frame.

Background

Generally, an entering/alighting structure of a vehicle such as a bus is constituted by steps installed at a front or middle portion of the vehicle. There is no particular inconvenience when the general public uses the getting on/off structure, but when using a baby carriage or a wheelchair, the baby carriage or the wheelchair is difficult to get on or off without the help of others.

Recently, in order to overcome the above problems and increase the convenience of getting on or off a bus, a ramp system (ramp system) is being installed in which pedals are selectively pulled out from the bottom of a bus to the ground.

Conventional ramp systems operate in a sliding manner. That is, a frame mounted on a bus body and a pedal moving relative to the frame are connected to each other by a slide mechanism so that the pedal is configured to slide on the frame. However, since the frame and the step are loosely coupled to make the step smoothly slide, the step may fluctuate side to side or up and down in the moving direction during the operation of the slope system. The fluctuation of the pedal causes a malfunction of the ramp system.

Therefore, in addition to the mechanism for sliding the pedal, an additional mechanism for preventing the pedal from fluctuating is introduced in the slope system. However, adding additional mechanisms for preventing pedal surge may increase the weight and cost of the ramp system. In addition, the weight increase of the ramp system may cause a decrease in fuel efficiency.

In general, a ball screw type mechanism or a chain type mechanism is employed as a mechanism for sliding the pedal. The chain mechanism has advantages in that cost and operation noise are reduced and foreign matter adhesion is prevented, compared to the ball screw type mechanism. However, according to the chain mechanism, noise or fluctuation of the pedal may occur during operation due to the characteristics of the chain in which the operational play exists.

The above information disclosed in this background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Disclosure of Invention

The present disclosure is directed to providing a slope system having advantages of weight reduction and cost reduction by adding a function of preventing a pedal from fluctuating to a mechanism for sliding the pedal.

In addition, another embodiment of the present disclosure provides a ramp system capable of preventing a play between components, thereby reducing noise of a chain type sliding mechanism.

A ramp system according to an exemplary embodiment of the present disclosure is configured to move a pedal disposed in a frame between a ramp closed position and a ramp open position along a moving direction. The ramp system may include: a drive device, comprising: a pair of sprockets spaced apart from each other along a moving direction, the pair of sprockets being rotatably provided in the frame, and a chain engaged with the pair of sprockets and movable along the moving direction and transmitting a driving torque to the pedal to move the pedal along the moving direction; and a tensioner including a tension rod rotatably installed in the frame, one end of the tension rod being connected to the tension spring to receive an elastic force, and a tension gear engaged with the chain being rotatably installed at the other end of the tension rod to apply a tensile force to the chain, wherein the tension rod includes a first arm having a free end connected to the tension spring, and a second arm connected to the first arm at a predetermined angle and having a free end on which the tension gear engaged with the chain is rotatably installed.

The tension gear may be rotatably mounted at the tie bar by a first pin, and the tie bar may be rotatably mounted on the frame by a second pin.

The first pin may include: a small diameter portion penetrating the tension rod and the tension gear in a height direction; and a large diameter part formed at upper and lower ends of the small diameter part and having a diameter larger than that of the small diameter part.

The first bushing may be disposed between the first pin and the tension gear in the radial direction.

A first washer may be disposed between the tension bar and the tension gear, and a second washer may be disposed between the large diameter portion of the first pin and the tension gear in a height (vertical) direction.

The second pin may include: a pin penetrating the draw bar and fixed to the frame; and a pin head formed at one end of the pin shaft in a height direction and having a diameter greater than that of the pin shaft.

The stop may be disposed in an opposite direction from the pin head relative to the drawbar.

A second bushing may be disposed between the second pin and the pull rod.

The second bushing may include a bushing head disposed heightwise between the pin head and the tie rod, and a cylindrical portion extending heightwise from the bushing head and disposed radially between the pin shaft and the tie rod.

The ramp system may further comprise: a pair of guide rails extending in the moving direction at both side portions of the frame in a lateral direction perpendicular to the moving direction; a slide frame hingedly connected to one end of the step in the moving direction; and rollers rotatably connected to both sides of the sliding frame in a lateral direction and rotatably provided on each of the guide rails to be movable along each of the guide rails by rotation of the rollers.

The roller may be in contact with each guide rail obliquely.

Each of the guide rails may include an upper guide rail mounted on an upper surface of the frame and extending downward, and a lower guide rail mounted on a lower surface of the frame and extending upward toward the upper guide rail. Both sides of the lower portion of the upper rail may be formed of the first slope such that the lower portion of the upper rail is tapered downward, and both sides of the upper portion of the lower rail may be formed of the first slope such that the upper portion of the lower rail is tapered upward.

A receiving groove recessed in a radially inner direction may be formed at a central portion of the roller in a lateral direction, and both sides of the receiving groove may be formed of second inclined surfaces corresponding to the first inclined surfaces.

According to the exemplary embodiments of the present disclosure, it is possible to reduce the weight and cost of a slope system by adding a function of preventing the fluctuation of a pedal and assisting the smooth sliding of the pedal to a guide rail and a roller for sliding the pedal. In addition, the fuel efficiency of the vehicle can be improved due to the weight reduction of the ramp system.

According to another exemplary embodiment of the present disclosure, by applying the tensioner to a chain for sliding a pedal, it is possible to prevent a gap from occurring between the chain and a sprocket, thereby reducing the occurrence of noise during operation.

Additionally, other effects of the exemplary embodiments of the present disclosure should be explicitly or implicitly described in the description provided herein. Various effects expected according to exemplary embodiments of the present disclosure will be disclosed in the description provided herein.

Drawings

The embodiments herein may be better understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify identical or functionally similar elements, and in which:

FIG. 1 illustrates a portion of a vehicle to which a ramp system according to an exemplary embodiment of the present disclosure may be applied, wherein the ramp system is in a ramp-off position;

FIG. 2 illustrates a portion of a vehicle to which a ramp system according to an exemplary embodiment of the present disclosure may be applied, wherein the ramp system is in a ramp open position;

FIG. 3 is a schematic view of a ramp system in a ramp closed position according to an exemplary embodiment of the present disclosure;

FIG. 4 is a schematic view of a ramp system in a ramp open position according to an exemplary embodiment of the present disclosure;

FIG. 5 is an exploded view of a ramp system according to an exemplary embodiment of the present disclosure;

fig. 6 is a schematic view illustrating a portion of a driving apparatus for a ramp system according to an exemplary embodiment of the present disclosure;

FIG. 7 illustrates a roller mounted on a rail in a ramp system according to an exemplary embodiment of the present disclosure;

FIG. 8 shows the rails and rollers as viewed in the direction 'VIII' in FIG. 7;

FIG. 9 is a cross-sectional view of FIG. 8;

fig. 10 is a perspective view of a tensioner according to an exemplary embodiment of the present disclosure;

FIG. 11 is a cross-sectional view taken along line A-A in FIG. 10; and

fig. 12 is a sectional view taken along line B-B in fig. 10.

It should be understood that the drawings referred to above are not necessarily drawn to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the disclosure. The particular design features of the present disclosure, including, for example, particular sizes, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment.

Detailed Description

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It should be understood that the terms "vehicle," "vehicular," "automobile," or other similar terms as used herein include motor vehicles, such as passenger cars in general, including Sport Utility Vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and trains, and including hybrid vehicles, hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum).

FIG. 1 illustrates a portion of a vehicle to which a ramp system according to an exemplary embodiment of the present disclosure may be applied, wherein the ramp system is in a ramp-off position; fig. 2 illustrates a portion of a vehicle to which a ramp system according to an exemplary embodiment of the present disclosure may be applied, wherein the ramp system is in a ramp open position.

Although the ramp system 10 is illustrated in the present specification and drawings as being mounted on a bus, it should be understood that vehicles on which the ramp system 10 may be mounted are not limited to buses.

As shown in fig. 1 and 2, a ramp system 10 according to an exemplary embodiment of the present disclosure is mounted on a bottom surface 2 of a body 1 of a vehicle. The vehicle body 1 is provided with a door 4 for a passenger to get on or off, and the ramp system 10 is mounted on a bottom surface 2 of the vehicle body 1 corresponding to the door 4. The ramp system 10 includes a frame 12 fixed to the bottom surface 2 of the vehicle body 1, and a step 14 that slides on the frame 12 in a moving direction to get in and out of the frame 12. Here, the "slope-closed position", as shown in fig. 1, represents a position where the step 14 enters the frame 12 as deeply as possible, and the "slope-open position", as shown in fig. 2, represents a position where the step 14 is located as far away from (extends from) the frame 12 as possible. Thus, the step 14 can slide on the frame 12 in the direction of movement between a ramp closed position and a ramp open position.

The tread 14 may be hingedly connected to a structure that slides within the frame 12 (e.g., a sliding frame 16). For example, as the deck 14 extends out of the frame 12, the deck 14 may rotate in a vertically downward direction by gravity. Thus, the free end of the step 14 at the ramp open position (e.g., the end furthest from the frame 12 at the ramp open position) contacts the ground to securely support the step 14 on the ground. Thus, the wheelchair or stroller can be safely moved on the steps 14. In addition, as the pedals 14 enter the frame 12, the pedals 14 may be rotated by the frame 12 to be substantially parallel to a bottom surface of the frame 12 (e.g., the lower frame 121). Therefore, the entrance and exit of the pedal 14 become smooth.

FIG. 3 is a schematic view of a ramp system in a ramp closed position according to an exemplary embodiment of the present disclosure; FIG. 4 is a schematic view of a ramp system in a ramp open position according to an exemplary embodiment of the present disclosure; FIG. 5 is an exploded view of a ramp system according to an exemplary embodiment of the present disclosure; and fig. 6 is a schematic view illustrating a portion of a driving apparatus for a ramp system according to an exemplary embodiment of the present disclosure.

As shown in fig. 3-6, the ramp system 10 further includes a sliding frame 16, at least one

guide rail

18a and 18b, at least one roller 20, a drive device 30, and a tensioner 70 mounted in the frame 12.

The frame 12 includes a lower frame 121, a pair of side frames 122, and an upper frame 123 connected to each other. The pair of side frames 122 connect both sides of the lower frame 121 and the upper frame 123 in a lateral direction perpendicular to the moving direction of the pedals 14, so that the frame 12 has a rectangular parallelepiped shape having an internal space therein. However, the shape of the frame 12 is not limited to a rectangular parallelepiped. At least a portion of the sliding frame 16, the at least one

rail

18a and 18b, the at least one roller 20, the drive device 30, and the tensioner 70 may be disposed in the interior space of the frame 12. Here, as shown in fig. 5, upper and lower portions of the side frames 122 extend in the lateral direction and are coupled to the upper frame 123 and the lower frame 121, respectively. It should be understood that the upper and lower portions of the side frames 122 extending in the lateral direction also constitute the upper frame 123 and the lower frame 121, respectively. Alternatively, the upper frame 123 and the lower frame 121 may be directly coupled to the top and bottom of the side frame 122, respectively.

The sliding frame 16 is configured to slide on the frame 12 in the direction of movement by at least one roller 20 provided at each side of the sliding frame 16 in the lateral direction. The pedal 14 is hingedly connected to one end of the slide frame 16 in the moving direction. Therefore, when the step 14 is protruded from the frame 12 or entered into the frame 12, by rotating the step 14 around one end portion of the slide frame 16 in the moving direction, the entering and exiting of the step 14 becomes smooth.

At least one

guide rail

18a and 18b is provided on at least one side of the frame 12 in the lateral direction. At least one

guide rail

18a and 18b extends in the moving direction, and at least one roller 20 provided on at least one side surface of the slide frame 16 in the lateral direction is rotatably provided at the at least one

guide rail

18a and 18 b. The sliding of the slide frame 16 becomes smooth by at least one

guide rail

18a and 18b and at least one roller 20, thereby preventing the fluctuation of the slide frame 16 and the step 14 connected to the slide frame 16. The

rails

18a and 18b and the rollers 20 will be described in more detail.

The driving device 30 generates a driving torque and transmits the generated driving torque to the pedal 14. When drive 30 is operated, pedals 14 and slide frame 16 connected to pedals 14 slide on frame 12, causing pedals 14 to enter or exit frame 12.

As shown in fig. 5 and 6, in one example, the drive device 30 may include a drive motor (not shown), a pair of sprockets 32 and a chain 34.

The driving motor is mounted on the bottom surface 2 of the vehicle body 1 or at any suitable position, and is connected to at least one of the pair of sprockets 32 to rotate the sprocket 32. The drive motor is connected to a power source (e.g., a battery, etc.) to receive electrical energy therefrom.

Each of the pair of sprockets 32 is spaced apart from each other in the moving direction and connected to each other by a chain 34. The chain 34 is connected to the pair of sprockets 32, and at least one of the pair of sprockets 32 is connected to the drive motor to be rotated by the drive motor. At this time, the chain 34 is moved in the moving direction by the rotation of the sprocket 32, and the pedals 14 mounted on the chain 34 and the slide frame 16 connected to the pedals 14 are also moved in the moving direction along with the chain 34. The pair of sprockets 32 are rotatably mounted on the lower frame 121 or the upper frame 123 and are positioned to move the step 14 between the ramp closed position and the ramp open position.

The tensioner 70 is connected to the chain 34 to apply a pulling force to the chain 34. The tensioner 70 will be described in more detail.

Referring to fig. 7-9, the

rails

18a and 18b and the rollers 20 are described in more detail.

FIG. 7 illustrates a roller mounted on a rail in a ramp system according to an exemplary embodiment of the present disclosure; FIG. 8 shows the rails and rollers as viewed in the direction 'VIII' in FIG. 7; fig. 9 is a sectional view of fig. 8.

As shown in fig. 7 to 9, the pair of

guide rails

18a and 18b are mounted on both side portions of the frame 12 in the lateral direction and extend in the moving direction, and a roller 20 is rotatably provided on each of the

guide rails

18a and 18 b.

Each of the

rails

18a and 18b includes an upper rail 18a mounted on the upper frame 123 and extending downward, and a lower rail 18b mounted on the lower frame 121 and extending upward toward the upper rail 18a, and the upper rail 18a and the lower rail 18b are disposed on the same vertical line.

Both sides of the lower portion of the upper rail 18a are formed as first inclined surfaces 19a such that a distance between the first inclined surfaces 19a of the upper rail 18a becomes narrower toward the bottom. Similarly, both sides of the upper portion of the lower rail 18b are formed as second inclined surfaces 19b such that the distance between the second inclined surfaces 19b of the lower rail 18b becomes narrower toward the top. That is, the lower portion of the upper rail 18a tapers downwardly, while the upper portion of the lower rail 18b tapers upwardly.

Each roller 20 is rotatably disposed between the upper rail 18a and the lower rail 18 b. When the roller 20 rotates between the upper rail 18a and the lower rail 18b, the roller 20 moves in the moving direction. The roller 20 has a shape such that two cylinders having a relatively large diameter are coupled to both surfaces of one cylinder having a relatively small diameter. Thus, the roller 20 is formed of a receiving groove 22 that is recessed in a radially inner direction at a central portion thereof in a direction of the rotation axis X (parallel to the lateral direction), and a lower portion of the upper rail 18a and an upper portion of the lower rail 18b are disposed in the receiving groove 22, so that the roller 20 is rotatably disposed between the upper rail 18a and the lower rail 18 b. Both sides of the receiving groove 22 are formed as third inclined surfaces 24 corresponding to the first inclined surfaces 19a and the second inclined surfaces 19b such that a distance between the third inclined surfaces 24 becomes narrower toward a radially inner direction. Thus, the rollers 20 obliquely contact the

guide rails

18a and 18 b. The inclined contact of the

rails

18a and 18b with the rollers 20 allows the rollers 20 to be in close contact with the

rails

18a and 18b over a wider range, thereby enabling the rollers 20 to rotate between the

rails

18a and 18b without undulation. Therefore, when the ramp system 10 is operated, the step 14 is prevented from fluctuating up and down and left and right with respect to the moving direction.

Each roller 20 is rotatably connected to the slide frame 16. In one example, the connection portion 40 is fixed to at least one side of the sliding frame 16 in a lateral direction, and the bolt 50 penetrates the roller 20 and the connection portion 40 in the lateral direction to be coupled with the nut 42. A bolt head 52 is formed at one end of the bolt 50 in a transverse direction, and a tool hole 54 into which a tool is inserted for rotating the bolt 50 is formed at the bolt head 52. In addition, a nut 42 is fixed to the connection portion 40. Thus, when the bolt 50 is coupled to the nut 42, the roller 20 is positioned between the bolt 50 and the connecting portion 40. However, since the bolt 50 is not coupled to the roller 20, the roller 20 is rotatably positioned between the bolt 50 and the connection portion 40. In addition, a bushing 60 extending in the lateral direction is provided between the bolt 50 and the roller 20 to smoothly rotate the roller 20.

In another example, the nut 42 is disposed on an opposite side of the roller 20 relative to the attachment portion 40, but is not secured to the attachment portion 40. Although the nut 42 is not fixed to the connection portion 40, when the bolt 50 penetrates the roller 20 and the connection portion 40 and is coupled to the nut 42, the roller 20 is rotatably positioned between the bolt 50 and the connection portion 40.

In further examples, the connection portion 40 may function as a nut by forming threads on the connection portion 40. In this case, the bolt 50 penetrates the roller 20 in a transverse direction and is coupled to the connection portion 40.

Referring to fig. 10-12, a tensioner 70 according to an exemplary embodiment of the present disclosure will be described in more detail below.

Fig. 10 is a perspective view of a tensioner according to an exemplary embodiment of the present disclosure; FIG. 11 is a cross-sectional view taken along line A-A in FIG. 10; and FIG. 12 is a sectional view taken along line B-B in FIG. 10.

As shown in fig. 10, the tensioner 70 includes a tension rod 72, a tension gear 76, a tension spring 74, and first and

second pins

91 and 101.

The pull rod 72 is rotatably mounted on the lower frame 121 or the upper frame 123 by a second pin 101, and includes a first arm 82 and a second arm 84. In this specification, it is exemplified that the pull rod 72 is rotatably mounted on the lower frame 121 via the second pin 101. In one example, the first arm 82 and the second arm 84 are integrally formed with each other, and the second arm 84 is bent at a predetermined angle with respect to the first arm 82. In another example, the second arm 84 may be formed separately from the first arm 82 and connected to the first arm 82 to form a predetermined angle therebetween. The predetermined angle between the first arm 82 and the second arm 84 and the shape of the pull rod 72 may be appropriately designed by a designer considering the direction of the elastic force acting on the pull rod 72 by the tension spring 74 and the direction in which the pull rod 72 applies the tensile force (tension force) to the chain 34 through the tension gear 76. The second pin 101 is installed at a position where the first arm 82 and the second arm 84 are joined, the tension spring 74 is installed at a free end portion of the first arm 82 to apply an elastic force to the first arm 82, and the tension gear 76 is installed at a free end portion of the second arm 84 through the first pin 91 to apply a tensile force to the chain 34. That is, the pull lever 72 rotates about the second pin 101 to convert the elastic force of the tension spring 74 into a pulling force, and is configured to apply a certain lever pulling force to the chain 34.

The tensioning gear 76 is rotatably mounted at the free end of the second arm 84 by a first pin 91. The tensioning gear 76 is provided with gear teeth 77 at its outer circumference to engage the chain 34.

As shown in fig. 11, the tension gear 76 includes a core portion 97 and a gear portion 98. The core 97 has a cylindrical shape with a predetermined height. The gear portion 98 has a circular plate shape, is formed at an upper or lower portion of the core 97, and is provided with gear teeth 77 formed at an outer circumference of the gear portion 98. To apply the proper pulling force to the chain 34, the tensioning gear 76 should be positioned within the closed loop formed by the chain 34 and push the chain 34 out of the closed loop. The pull rod 72 extends across the chain 34 to a tension gear 76. The draw bar 72 crosses the chain 34 above or below the chain 34 so that the chain 34 and the draw bar 72 do not interfere with each other, the core 97 extends downward or upward, and the gear portion 98 is formed at an upper portion or a lower portion of the core 97.

In addition, the tension gear 76 is mounted on the lower or upper surface of the pull rod 72 by a first pin 91. The first pin 91 includes a small diameter portion 92 having a cylindrical shape and extending in the height direction, and a pair of large diameter portions 93 formed at lower and upper ends of the small diameter portion 92 and having a diameter larger than that of the small diameter portion 92. The tension rod 72 and the tension gear 76 are disposed between the pair of large diameter portions 93. The small diameter portion 92 of the first pin 91 penetrates the first pin hole 111 formed at the tension rod 72 and the gear hole 99 formed at the tension gear 76 in the height direction, and the large diameter portion 93 of the first pin 91 mounts the tension gear 76 at the tension rod 72. For this reason, the small diameter portion 92 has a diameter smaller than the diameter of the first pin hole 111 and the diameter of the gear hole 99, and the large diameter portion 93 has a diameter larger than the diameter of the first pin hole 111 and the diameter of the gear hole 99. In addition, a first bushing 96 is provided between the small diameter part 92 of the first pin 91 and the tension gear 76 in the radial direction, and washers 94 are provided between the tension rod 72 and the tension gear 76 and between the tension gear 76 and the large diameter part 93 of the first pin 91 in the height direction, respectively, to smoothly rotate the tension gear 76.

A tension spring 74 is mounted between the free end of the first arm 82 and the frame 12 to apply a spring force to the pull rod 72.

The second pin 101 rotatably mounts the pull rod 72 on the frame 12 to serve as a rotation center of the pull rod 72. As shown in fig. 12, the second pin 101 includes a pin head 102 and a pin shaft 103. A pin head 102 is formed at an upper end or a lower end of the pin shaft 103, and the pin shaft 103 extends in a direction opposite to the pin head 102. In addition, a stopper 108 is provided in the opposite direction of the pin head 102 of the second pin 101 with respect to the draw bar 72 to prevent the draw bar 72 from fluctuating in the height direction. The stopper 108 is connected to the second pin 101 or the frame 12 to support the draw bar 72 in the height direction. Therefore, the pin shaft 103 penetrates the second pin hole 113 formed at the pull rod 72 and the stopper hole 109 formed at the stopper 108 in the height (vertical) direction, and is fixed to the lower frame 121 or the upper frame 123. That is, the draw bar 72 and the stopper 108 are disposed between the pin head 102 and the lower frame 121 or the upper frame 123. For this reason, the diameter of the pin head 102 is larger than the diameter of the pin shaft 103, the diameter of the second pin hole 113, and the diameter of the stopper hole 109, and the diameter of the pin shaft 103 is smaller than the diameter of the second pin hole 113 and the diameter of the stopper hole 109. In addition, a second bushing 104 is provided at least between the pull rod 72 and the second pin 101 in order to smoothly rotate the pull rod 72. In one example, second bushing 104 includes a bushing head 105 and a cylindrical portion 106 extending from bushing head 105 in a height direction. The bushing head 105 is arranged in the height direction between the pin head 102 and the tie rod 72, and the cylindrical portion 106 is arranged in the radial direction between the pin shaft 103 and the tie rod 72 and/or the stop 108. Additionally or alternatively, an additional washer may be provided between the tie rod 72 and the stop 108 in the height direction. The tensioner 70 prevents play between the chain 34 and the sprocket 32 by applying a pulling force to the chain 34, thereby preventing noise from being generated.

According to the exemplary embodiment of the present disclosure, by mounting the upper and

lower rails

18a and 18b on both sides of the frame 12 in the lateral direction and rotatably disposing the rollers 20 between the upper and

lower rails

18a and 18b, lateral and vertical undulations of the step deck 14 may be prevented during operation of the ramp system 10.

In addition, by bringing the upper rail 18a and the lower rail 18b into oblique contact with the roller 20, the lateral and vertical undulations of the step plate 14 can be further prevented.

Further, the weight and cost of the slope system 10 can be reduced by adding a function of preventing the fluctuation of the step 14 to the mechanism for sliding the step 14. Therefore, the fuel efficiency of the vehicle can be improved.

In addition, by applying a pulling force to the chain 34 by the tensioner 70, the occurrence of a backlash between the chain 34 and the sprocket 32 can be prevented. Therefore, the generation of noise can be prevented.

While the present disclosure has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A ramp system configured to move a step disposed in a frame in a direction of movement between a ramp closed position and a ramp open position, the ramp system comprising:

a drive device, comprising: a pair of sprockets spaced apart from each other along the moving direction, the pair of sprockets rotatably disposed in the frame; and a chain that is engaged with the pair of sprockets and is movable in the moving direction, and transmits a driving torque to the pedal to move the pedal in the moving direction; and

a tensioner including a tension rod rotatably installed in the frame, one end of the tension rod being connected to a tension spring to receive an elastic force, and a tension gear engaged with the chain being rotatably installed at the other end of the tension rod to apply a tension force to the chain;

wherein the tension lever includes a first arm having a free end connected to the tension spring and a second arm connected to the first arm at a predetermined angle and having a free end rotatably mounting the tension gear engaged with the chain.

2. The ramp system according to claim 1, wherein the tension gear is rotatably mounted on the pull rod by a first pin and the pull rod is rotatably mounted on the frame by a second pin.

3. The ramp system according to claim 2, wherein the first pin comprises:

a small diameter portion penetrating the tension rod and the tension gear in a vertical direction; and

a large diameter portion formed at upper and lower ends of the small diameter portion and having a diameter larger than that of the small diameter portion.

4. The ramp system according to claim 2, wherein a first bushing is disposed in a radial direction between the first pin and the tension gear.

5. The ramp system according to claim 3, wherein a first washer is disposed between the tie rod and the tension gear and a second washer is disposed in the vertical direction between the large diameter portion of the first pin and the tension gear.

6. The ramp system according to claim 2, wherein the second pin includes:

a pin penetrating the draw bar and fixed to the frame; and

a pin head formed at one end of the pin shaft in a vertical direction and having a diameter greater than that of the pin shaft.

7. The ramp system according to claim 6, wherein a stop is provided in an opposite direction of the pin head relative to the tie rod.

8. The ramp system according to claim 6, wherein a second bushing is disposed between the second pin and the pull rod.

9. The ramping system according to claim 8, wherein the second bushing comprises:

a bushing head disposed between the pin head and the tie rod in the vertical direction; and

a cylindrical portion extending from the bushing head in the vertical direction and disposed between the pin and the tie rod in a radial direction.

10. The ramping system according to claim 1, further comprising:

a pair of guide rails extending in the moving direction at both side portions of the frame in a lateral direction perpendicular to the moving direction;

a slide frame hingedly connected to one end of the pedal in the moving direction; and

a roller rotatably connected to both sides of the sliding frame in the lateral direction and rotatably provided on each guide rail to be movable along each guide rail by rotation of the roller.

11. The ramp system according to claim 10, wherein the roller contacts each rail at an incline.

12. The ramping system according to claim 11, wherein,

each of the guide rails includes an upper guide rail mounted on an upper surface of the frame and extending downward, and a lower guide rail mounted on a lower surface of the frame and extending upward toward the upper guide rail, and

wherein both sides of a lower portion of the upper rail are formed as first slopes such that the lower portion of the upper rail is tapered downward, and both sides of an upper portion of the lower rail are formed as second slopes such that the upper portion of the lower rail is tapered upward.

13. The ramping system according to claim 12, wherein,

the roller includes a central portion having a receiving groove in the lateral direction, the receiving groove being recessed in a radially inner direction, and both sides of the receiving groove are formed as third inclined surfaces corresponding to the first inclined surfaces on the upper rail and the second inclined surfaces on the lower rail.